Acute ischemic stroke: a rare complication of hump-nosed pit viper (Hypnale spp.) bite: a case report

Acute ischaemic stroke and deep vein thrombosis following snakebite

Snakebite envenomation remains a neglected tropical public health issue claiming thousands of lives every year. It is a common medical emergency and a threat to the impoverished populations of low-income and middle-income countries including India. A combination of ischaemic stroke and deep vein thrombosis is a devastating duo complication of snake bite, with no literature report to date. Here, the authors report an unusual case of a young woman developing ischaemic stroke and deep vein thrombosis following snakebite even after the use of antivenom. MRI brain showed right thalamic infarct with haemorrhagic transformation and, ultrasound Doppler revealed right lower limb deep vein thrombosis. The pathophysiology of deep vein thrombosis and ischaemic stroke is complex. It is believed that the activation of the coagulation cascade, complement system together with endothelial injury and immune activation leads to inflammation, thrombosis and occlusion of smaller and even larger vessels.

Thromboembolic events following a pit viper bite from Protobothrops mucrosquamatus (Taiwan Habu): A report of two cases

Protobothrops mucrosquamatus, also known as the Taiwan Habu, is a venomous snake prevalent in Taiwan. It is accountable for most snakebites in the region. The toxin of the Taiwan Habu has significant hemorrhagic potential. However, patients bitten by this snake often suffer more local injuries than systemic ones. This report presents two cases of individuals bitten by the Taiwan Habu who subsequently experienced thromboembolism. In the first case, an 88-year-old male, bitten on his fourth toe, suffered a cerebral infarction 32 hours post-bite. In the second case, an 82-year-old female, bitten on her ankle, experienced cardiac arrest 19 hours later. Both patients promptly received antivenom and showed no signs of coagulopathy either before or after the snakebite. However, elevated coagulation factor VIII levels were observed in the first case. Our aim is to understand the mechanism behind these thromboembolic events. This report emphasizes the unusually high level of coagulation factor VIIIa and highlights the need for further investigation into the mechanisms involved. Consequently, physicians should assess the risk of thromboembolic events in snakebite patients by evaluating coagulation factors during treatment.

Long-term health manifestations of hump-nosed pit viper (Genus: Hypnale) bites

INTRODUCTION

The hump-nosed pit viper (Genus: Hypnale) is a highly medically significant snake in Sri Lanka, responsible for the majority of venomous snakebites (22-77%). They are found throughout Sri Lanka and the Western Ghats region of India. The venom can lead to two types of effects: acute and long-term. Acutely, bites often result in local symptoms, with less common systemic effects such as acute kidney injury, venom-induced consumption coagulopathy, and thrombotic microangiopathy.

METHODS

We conducted a prospective observational study at Teaching Hospital Ratnapura, Sri Lanka, spanning six years, starting in June 2015. Patients bitten by hump-nosed pit vipers were followed up for two years, with assessments every three months to identify long-term effects. Data was gathered through interviewer-administered questionnaires.

RESULTS

Out of 728 patients bitten by hump-nosed pit vipers, 22 (3%) were lost to follow-up. Forty-four (6.2%) experienced long-term effects, including chronic kidney disease (24; 3.4%), chronic wounds (five; 0.7%), amputations (five; 0.7%), fasciotomy-related wounds (four; 0.6%), and psychological illnesses (four; 0.6%). There were nine (1.3%) deaths in this group. Among those with chronic effects, 27 (61%) were males, and 17 (39%) were females, with ages ranging from 29 to 82 years (mean 57.6 years). The time it took to diagnose acute kidney injury from the snakebite was 18 h (interquartile range: 15-23.5 h), while the time to diagnose chronic kidney disease was 69 days (interquartile range: 64-74.75 days). In these patients, the estimated glomerular filtration rate was 29.3 mL/min/1.73 m2 (interquartile range: 14-50.75 mL/min/1.73 m2). Among the patients who did not develop long-term complications (662; 91%) 660 (90.7%) experienced local effects, and 82 (11.3%) developed systemic manifestations, including acute kidney injury in 60 (8%) and coagulopathy in 35 (5%).

CONCLUSION

Following hump-nosed pit viper bites, a subset of patients may experience long-term health complications, including chronic kidney disease, chronic ulcers, amputations, fasciotomy-related wounds, and psychological illnesses, with chronic kidney disease being the most frequently observed among these manifestations.